Abstract：In view of both selection of main control factors and their weights determination, which have a greater subjectivity in the forecasting process of water inrush from coal mine floor, using the vulnerability index method, fractal-vulnerability index method was put forward. Wangxingzhuang mine was used as an example to evaluate the water inrush risk of limestone aquifer L_1-4in the lower section of Taiyuan formation in coal seam B₁based on the fractal-vulnerability index method. It was the four main control factors, i. e. the water pressure in the lower limestone aquifer, the permeability of the limestone aquifer in the lower part of Taiyuan formation, the unit water inflow, and the equivalent thickness of the effective water barrier, that were used to quantify the properties of the aquifer and the aquifuge. With fault fractal dimension, the comprehensive nature of faults could be quantitatively quantified. The weights of the above five main control factors were determined by AHP, and the zoning maps were obtained with GIS. The results showed that the fragile area were mainly located in the northwest of the study area. Therefore, Moreover, the measured water burst was located in the fragile area of the predicted zoning map. The fractal-vulnerability index method reduces the number of main control factors ( the previous studies at least require three factors to quantify the fault) , which can improve the prediction accuracy of coal mine floor water inrush.

Keyword：fractal-vulnerability index method;floor water inrush prediction;fractal dimension;Wangxing zhuang mine;